I recently bought a 2005 vette with 60k miles from a Chevy dealership in Dallas. As soon as i got in to test drive it, the check engine light was on. It ran fine wasnt making any unusuall noises or anything. The dealership explained that it was because they had just put a new battery on it because whoever parked it the last time didnt put it in reverse. I had read on here about problems with the battery when not left in reverse. Seemed like a good enough explanation to me and they turned the light off i drove it some more and it didnt come back on so I didnt think to much about it.

Well I buy it and drive it home 3 hours and light stays off, not noises or anything, seems fine. Then I get in it the next day and crank it and in less than 5 minutes the check engine light is back on. I take it to a mechanic who reads the code and advises the code is coming because of the camshaft position sensor. He advises it is more than likely just a bad sensor. He recommended a shop for me to take it to and have them tune it and check the sensor. I called that shop and ordered some shocks as the ones on it were wore out and ask them to tune it and check the sensor while its there. Well I keep driving for a couple weeks and the light seems to come on and go off at random until they get my parts in and i take to to have the shocks put on and the tune. They seemed alot more concerned about the sensor. The advised it was most likely 1 of 3 problems.

1. Bad sensor (sensor would have to be replaced to fix but they would need to remove a few other parts to be able to get to the sensor, but not near as many as #3 below)
2. Wires from sensor may be loose (reseat the plug should fix)
3. The camshaft bolts could be loose/backing out alowing the camshaft to move a little and cause the code. (The bolts would need to be tightened to fix but they would have to take A LOT of other parts off of the car that are in the way of getting in there to tighten = labor intensive = not cheap)

While they had it in the shop they unplugged the sensor and plugged it back in to reseat the plug and the light went off. They drove it around checking to make sure that there wasnt any noise in the suspension and the light didnt come back on. They did the tune and everything, light still didnt come back on. They drove it some more to test the tune and it still didnt come back on. I go pick it up and drive it home (hour drive) and the light is still off and all seems well. I get back in the next day crank it up and the engine light came back on before i even get from the garage to the street.

So now Ive got to figure out what the heck is causing this. I need to either have them replace the sensor or tighten the bolts they advised may be allowing the camshaft to move.

Dosn't sound like im going to get off very cheap on this eiather way

Does anybody know how big of a job it is to replace the camshaft position sensor? About how many hours of labor should i expect?

 

Cam position sensor is easy fix. Just have to remove water pump to gain access. Takes about an hour. I would start there. I doubt your cam sprocket is moving around due to loose bolts.

I'd replace both the sensor and harness since they arn't that expensive.

Generally the car will hard start (crank over for 5-10 seconds) and backfire upon start up when you have a bad cam sensor.

 

That's part of my worry. I read that about the hard starting on another thread. Mine had never had hard start at all. Always fires right up...

Is there not a way to test these parts other than just put a new one on and see if the issue goes away?

 

I have a 2006, C6 and replaced the cam position sensor in abut ten minutes. You do not have to remove the water pump. Sensor is held on with one bolt with a ten millimeter head. Were the bolt loose, it could cause what you have described. I did mine from below. The sensor was just over $50 from a Chevy dealer.

 

I wish it was that easy for me. With oil scavenge pump and lines, piping etc from turbo's it's usually easier to do most repairs from the top. Not sure how you can get both screws out of cam sensor harness braket (if replacing both sensor and harness) from underneath unless you have dwarf hands.

 

I have a similar issue with my '05, 75k miles. I checked the codes and I swear it said crank sensor, but maybe it was the cam sensor; since I've never heard of a cam sensor my mind read it as crank.

Anyway, I clear the codes and it goes away, once in awhile it comes back. Much less frequently than etx's, so I haven't worried about it. I guess I need to pay attention to the actual code next time!

 

Has to be cam sensor. Like DSOMC6 said, a bad cam sensor will cause a hard start issue, but with a bad crank sensor, the engine won't even turn over.

 

Those sensors are magnetic. When you pull it out, look for marks or any metal shavings on them.

While it doesn't happen all of the time, I have seen the cam bolts back out of the cam and rattle the front cam gear loose. Sometimes you will see marks on the sensor. If you see metal on there, for sure have them take the front cover off and inspect not only the cam gear but also the cam retaining plate as well.

While it could be something as simple as a connector or bad sensor, it is worth looking into a bit more before something else goes wrong if that is what is triggering the problem to begin with.


This is something that you could do at home if you have the tools to do so. Easiest thing to do is to pull the water pump, and the sensor is located in the front timing cover, and held in with one bolt. Pull the bolt, un-plug and replace. That way you know for sure if there is any metal stuck to it. The sensors themselves are pretty cheap, $40-50 at best.

 

I got a hard start and cam sensor code, ( RPM tach stopped working)( ragged idle and not smooth while driving alt meter reading 14.5 amps.) all because of a bad battery, I wonder how many people have changed out cam sensor module all because of a bad battery.

 

Thank you, everyone. A new cam sensor fixed my z06; would crank for a few seconds before firing. I didn't have a code & after starting, it would run fine. Well, now it runs much better on the low end. Thank you for your help.